This invention relates to bases for a fluorescent lamp and, in particular, to a base for an annular fluorescent lamp.
In the prior art, annular fluorescent lamp bases typically comprised two halves fastened together with a self-tapping screw, wherein each half comprises a thermosetting, compression-molded plastic. In addition, the bases were typically designed to have an outside diameter (o.d.) approximately equal to the diameter of the tubing from which the lamp is made. Thus, the base had to fit between the ends of the lamp. Since manufacturing tolerances permit some variation in the end spacing, it was necessary to stock a number of bases of different sizes. The bases of the prior art were thus expensive to manufacture and assemble.
Some bases of more recent design, e.g., U.S. Pat. Nos. 3,858,162 and 3,898,495, utilize a snap-lock design to simplify assembly of the base, eliminating the need for the self-tapping screw. The fabrication of the base parts, however, requires complicated and expensive tooling for the enclosed undercuts. Further, both require flexing of the outside wall of the base for disassembly, whereas rigid outside walls are preferred. In addition, the bases are difficult to disassemble due to the use of two interlocking elements.